Bacteria that effectively transform plastic waste into a useful eco-friendly plastic:
Bacteria that effectively transform plastic waste into a useful eco-friendly plastic:
In
response to problems associated with plastic waste and its effect on
the environment, there has been considerable interest in the development
and production of biodegradable plastics. Innumerable amount of
research have also been conducted world wide to find out ways to convert
synthetic plastic waste into biodegradable and compostable material.
Their effort was to isolate bacterium that can effectively convert a
waste plastic product into safe, biodegradable product or to make safe
and biodegradable plastic, which can be used safely for further
manufacture of some product.
A.
It has been observed that, chemicals called Polyhydroxyalkanoates
(PHAs) are polyesters that accumulate as inclusions in a wide variety of
bacteria. These bacterial polymers have properties ranging from stiff
and brittle plastics to rubber-like materials. Because of their inherent
biodegradability, PHAs are regarded as an attractive source of
nonpolluting plastics and elastomers that can be used for specialty and
commodity products. They
were the first biodegradable polyesters to be utilised in plastics.
These aliphatic polyesters naturally produced via a microbial process on
sugar-based medium. The two main members of the PHA family are
polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV).
B. There is good news that, recently some European scientists have
discovered a bacterial strain that uses styrene, a toxic byproduct of
the polystyrene industry, as fuel to make Polyhydroxyalkanoate (PHA) -
biodegradable plastic. The microbes, a special strain of the soil
bacterium Pseudomonas putida, convert polystyrene foam — commonly known
as Styrofoam — into PHA, a biodegradable plastic. This is among the
first to investigate the possibility of converting a petroleum-based
plastic waste into a reusable biodegradable form.
Researchers
utilized pyrolysis, a process that transforms plastic waste materials
by heating them in the absence of oxygen, to convert polystyrene — the
key component of many disposable products — into styrene oil. The
researchers then supplied this oil to Pseudomonas putida, a bacterium
that can feed on styrene, which converted the oil into PHA. The process
might also be used to convert other types of discarded plastics into
PHA.
C.
PHA has numerous applications in medicine and can be used to make
plastic kitchenware, packaging film and other disposable items as well.
This biodegradable plastic is resistant to hot liquids, greases and
oils, and can have a long shelf life. The advantageous side of PHA is
unlike polystyrene, it readily breaks down in soil, water, septic
systems and backyard composts. In other words, it is biodegradable and
compostable.
D.
Worldwide, more than 14 million metric tons of polystyrene are produced
annually, most of this ends up in landfills producing pollution. Thus,
this system can help transform plastic waste into a useful eco-friendly
plastic, significantly reducing the environmental impact of this
ubiquitous, but difficult-to-recycle waste stream.
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